Question
I have a dogwood with about a 6 inch diameter trunk and a very nice shape. We just moved to this house and the front yard was re-graded. It looked great all spring and into the summer but I think the roots of the dogwood were covered over with 4 to 6 inches or so of dirt and now the tree is in real distress with about half of its foliage dead and the rest turning yellow. If I uncover the roots can the tree recover?

Answer
Probably will do more damage if you remove the dirt unless you gentility remove it with by hand. Sounds like the roots were damaged during the grading either by the removal of soil , compaction of the machinery driving over the root zone or the added soil. If roots are damaged the tree will respond by dying back an equal amount of foliage. The roots system that was left could not supply the needs of the amount of foliage so some must be dropped. I assume you have sodded over the added soil and this will need to be moved before the soil is removed. You may just hope for the best and next spring prune off the dead branches and let any green foliage be the new crown. The tree may look ragged for a couple of years but IF you have foliage next spring it should live. Sorry!